1. Field of the Invention
The present invention relates to a film removing device for and a film removing method of removing a film from, for example, photomask substrates, namely, reticles, and glass substrates for FPDs (flat panel displays).
2. Description of the Related Art
Generally, processes for manufacturing, for example, photomasks and liquid crystal displays (LCDs), similarly to semiconductor device fabricating processes, uses photolithography for forming, for example, a thin film of ITO (indium tin oxide) or a circuit pattern on a substrate. For example, a resist solution application process applies a resist solution to a surface of a substrate so as to form a resist film, an exposure process exposes the resist film so as to form a latent circuit pattern in the resist film, and a developing process develops the latent circuit pattern so as to form a circuit pattern.
A coating method what is called the spin coating method is used widely by the resist solution application process. It occurs sometimes, when a resist solution is applied to a substrate by the spin coating method in the resist solution application process, that the resist solution is attracted to a peripheral part of the substrate by the agency of surface tension after the rotation of the substrate is stopped and any centrifugal force acts on the film of the resist solution, and the thickness of a part of the film of the resist solution on the peripheral part of the substrate increases. In some cases, part of the resist solution poured onto the upper surface of the substrate flows around the edge of the substrate to the lower surface of the substrate to form an unnecessary resist film on a peripheral part of the substrate. Such an unnecessary resist film needs to be removed.
A known thin film removing device (method) disclosed in US 2004/0226916 A1 includes approach stages disposed close to the periphery of a substrate supported on support members and including flat approach parts respectively having surfaces flush with the surface of the substrate. The entire content of US 2004/0226916 A1 is incorporated herein by reference. In this known thin film removing device (method), a removing unit jets a solvent toward the peripheral part of the substrate and the removing unit sucks a solution produced by dissolving the thin film in the solvent, while the removing unit is being moved along the peripheral part of the substrate and the approach stage. This thin film removing device (method) can remove straight parts of the thin film on the corners of the substrate and can suppress the creation of mist.
However, in some cases, the thin film removing device (method) cannot suck all the solution wetting the side surfaces of the substrate. In some cases, the solution wetting the side surfaces of the substrate flows onto the upper surface of the substrate and forms stains in part of the thin film on the corners of the substrate. The stains formed in the thin film spoils the appearance of the substrate. If part of the thin film for forming a circuit pattern is stained, the thin film cannot be used for forming the circuit pattern.